Conventionally, a so-called real-image viewfinder, where an image formed by an objective optical system is inverted into an erect image by an erect optical system, and the erect image is observed via an eyepiece optical system, is used as a viewfinder. Further, with a digital camera including an imaging optical system and a viewfinder which are separately formed where the imaging optical system has a magnification changing function, a viewfinders having a magnification changing function is often used so as to be able to accommodate an imaging angle of view and a zoom ratio of the imaging optical system. In recent years, high-quality digital cameras provided with a this type of real-image variable-magnification viewfinder are being introduced into the market. As a real-image variable-magnification viewfinder having a relatively high zoom ratio, those disclosed in Japanese Unexamined Patent Publication Nos. 8(1996)-122856, 2009-002991 and 2010-039339 (hereinafter, Patent Documents 1, 2 and 3, respectively), for example, are known.